Application of FMEA method in detailed assessment phase of ships’ critical systems

Abstract

Failure mode and effects analysis (FMEA) is a systematic method of analysis that has a well-established position in traditional reliability analyses. The objective of the FMEA is to assess and identify potential failures of system components as well as to assess the effects of failures on the system, and to propose countermeasures to prevent adverse effects. Due to the universal nature of the FMEA, it is possible to tailor and apply it in different ways depending on the objectives. The FMEA has a wide popularity and different interpretations, practices and standards of procedure.

The suitability of the FMEA is well managed at the equipment and system levels, where potential failure modes are generally known and the task is to analyse their effects on system operation. Today, passenger ship systems are extensive and complex, so the International Maritime Organization (IMO) has suggested a desire to apply the FMEA methodology to ship systems as well. This Master’s Thesis examines the applicability of the FMEA in a detailed assessment phase, in which the ship’s critical systems are analysed. The purpose of the detailed assessment phase is to ensure and guarantee that the systems in the event of a fire or flooding comply with SOLAS (Safety of Life at Sea) regulations. These regulations are also known as Safe Return to Port (SRtP). The SRtP regulations impose operational requirements on the systems to allow a ship to return safely to the nearest port in the event of an emergency.

The case company of this thesis has its own approach for the FMEA method. The research problem was to find out whether the FMEA method proposed by the IMO is suitable for the detailed assessment phase and whether the method corresponds to the way the case company performs the analysis. The aim of the research was to deepen the understanding of how the FMEA method could be applied to ship systems in the SRtP context. The SRtP regulations are goal-based in nature, so they do not provide guidelines on the FMEA method and no previous research has been conducted on the subject. Another objective of the research was to improve detailed assessment phase for the case company by proposing how the information obtained from the literature could be applied in the case company.

The thesis was carried out as a qualitative case study for the case company’s FMEA in the detailed assessment phase. The research methods used were literature review, thematic interview and content analysis. With the help of the literature, the theoretical framework of the research was formed, which provided the basis for the main concepts of the research and the FMEA methodology. In the empirical part of the work, the initial situation was investigated with internal documents of the case company and by performing an example exercise in order to get a practical picture of the assessment process. Thematic interviews were aimed at experts to gain more in-depth information. The content analysis condensed the research data and found out the interviewees views on the FMEA, challenges and development ideas.

As a result of the empirical part, it became clear that the FMEA of the case company is a simplified version, in which the failure concept is treated binary 1 (up/intact) or 0 (down/affected). due to the compliance of the regulations and the qualitative nature of the analysis process, a criticality analysis based on casualty scenarios was not considered necessary. The case company’s FMEA table was finalised by improving its failure effect review as a local and end response. Further research and development would be to utilise a relational database throughout the process model, which would help reduce the amount of manual work. This study deepened the understanding of the FMEA method in SRtP ship systems